prism application context

i want to design one class served as application context across prism based application ,for example i have one domain object
Group which has a children collection of type Contact
,now the ObservableCollection<GroupInfo> Groups collection live in one module ,but i want this be used all over the application in order to check some state and information .

i don't want to put it in the region context ,i suppose it should look like ThreadContext.Current .Groups ,any idea ?

You might find
shared services useful to fulfill your requirement; shared services are services shared among your modules by exporting them into the container, using the service's interface (which is stored in an infrastructure project referenced in all your modules)
as the contract type.

You might, therefore, create a service that returns your Groups, and abstracts the way you fetch it from the server (or any other place you're obtaining the groups from). You might find this blog post useful, which shows how to do this with WCF Services: